from typing import List
import sys

def LMI() -> List[int]:
    """Read multiple integers from input"""
    return list(map(int, input().split()))

def LMF() -> List[float]:
    """Read multiple floats from input"""
    return list(map(float, input().split()))

def LI(n: int) -> List[str]:
    """Read n strings from input"""
    return [input() for _ in range(n)]

def RIM(rows: int, cols: int) -> List[List[int]]:
    """Read a matrix of integers"""
    return [LMI() for _ in range(rows)]

def MII():
    """Read multiple integers from input as a map"""
    return map(int, sys.stdin.readline().split())

def II():
    """Read a single integer from input"""
    return int(sys.stdin.readline())

def FI():
    """Read a single float from input"""
    return float(sys.stdin.readline())


def solve() -> None:
    try:
        t = II()
        outs = []
        for _ in range(t):
            l,r = MII()
            outs.append((r-2*l+1)*(r-2*l+2)//2)
        print(*outs,sep="\n")
        
    except (EOFError, KeyboardInterrupt):
        pass

# =============================================================================
# MAIN EXECUTION
# =============================================================================

if __name__ == "__main__":
    # For multiple test cases, uncomment:
    # t = int(input())
    # for _ in range(t):
    #     solve()
    
    # For single test case:
    solve()
# 